Chapter 7 Outline

Chapter 7 Outline - Chapter 7 Prokaryotic Genetics...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 7 Prokaryotic Genetics Introduction 7.1 Prokaryotic DNA Prokaryotic DNA Is Organized within the Nucleoid Most of the genetic information in prokaryotic cells is contained in the chromosome The chromosome is located in the nucleoid DNA within a Chromosome Is Highly Compacted DNA occupies around 1/3 of the total volume of the cell The chromosome is supercoiled – twisted and tightly packed by nucleoid-associated proteins Many Prokaryotic Cells also Contain Plasmids Plasmids are stable extrachromosomal DNA elements that carry nonessential genetic information They replicate independently from the chromosome F plasmids allow genetic material to be transferred from a donor cell to a recipient R plasmids carry genes for antibiotic resistance 2. DNA Replication DNA Replication Is a Highly Regulated Process The first stage of prokaryotic replication is initiation, where DNA unwinds and the strands separate The point where replication starts is the origin of replication ( ori C) As the DNA unzips, two replication forks form and move in opposite directions away from the origin The second stage is elongation, when enzymes synthesize a new strand to pair with each original strand Insertion of complementary nucleotides on the template strand is carried out by DNA polymerase III DNA polymerase III can move only in a 3’ to 5’ direction, creating a leading strand and a lagging strand The lagging strand is synthesized in Okazaki fragments, which are joined by DNA ligase Mistakes that occur in DNA replication are called mutations The third stage is termination, when the two DNA helices separate from each other
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/17/2009 for the course MIC 201 taught by Professor Lacroix during the Spring '08 term at Rhode Island.

Page1 / 3

Chapter 7 Outline - Chapter 7 Prokaryotic Genetics...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online